1. Field of the Disclosure
The disclosure relates to a method for access verification by means of which the access of authorized persons to a protected area is permitted while the access of unauthorized persons is prevented, and to a device for access control as well as to an elevator car.
2. Related Technology
Many access control systems are known for preventing unauthorized entry into protected areas, especially buildings or certain areas of buildings.
Known access control systems involve checking each person seeking entry.
International Patent Publication WO 01/07353 A1, for example, discloses an elevator with access monitoring. The access monitoring is made possible by two physically separated motion detectors whose receiving field characteristics differ from each other, whereby one motion detector is attached to the elevator and the other is attached outside of the elevator. The motion detectors are designed in such a way that a person passing through the receiving field triggers a signal in the receiver of the motion detector.
Depending on the time sequence of the signals triggered in the pertinent receiver, a determination is made as to whether the person is moving into or out of the elevator.
Moreover, signals from transmitters present on persons are registered and evaluated. An authorization check is made on the basis of the evaluation of the transmitter signals. The authorization check as well as the signals of the motion detectors are used to determine whether a person who is accessing a certain floor is authorized to do so.
European Patent Publication EP 940 775 A2 discloses a passage lock and a method to operate such a passage lock. The passage lock has contact-free access control means based on a transponder system. Moreover, the sensors on the doors of the passage lock allow registration of the number of persons moving through the lock.
Furthermore, European Patent Publication EP 832 839 A1 discloses an identification system for an elevator installation. An elevator user carries an information transmitter, whereby the information transmitter sends individual data such as, for example, weight and height of the elevator user as well as a desired floor of the building to a recognition device inside the elevator. The described information transmitter uses electromagnetic waves for transmitting the information.
Moreover, a separate unit determines the momentary weight of the elevator.
When an elevator user enters the elevator, a comparator compares the measured increase in the weight of the elevator to the transmitted weight data of the elevator user who has entered. If the measured increase in the weight of the elevator and the transmitted weight data match, then the comparator sends a release signal to an elevator control unit so that the elevator is activated.
Elevator users without information transmitters are detected through the determination of the increase in the weight of the elevator, whereby the determination of an increase in the weight of the elevator for which there is no transmitted weight data causes an interruption in the elevator service.
U.S. Pat. No. 4,847,485 describes means to determine the number of persons and direction of movement inside a monitored room or a pass-through. At least two infrared sensors installed in a passage area at a fixed angle measure the ambient temperature over the course of time. The passage area can only be entered by using an identification reader so that the specific temperature patterns are used to check whether the number of persons who have entered the passage area is equal to the number of identification cards detected by the identification card reader.